import objectAssign from '../../../common/utils/merge';
import { markNodeData, NODE_KEY } from './util';

const reInitChecked = function(node) {
	const siblings = node.childNodes;

	let all = true;
	let none = true;

	for (let i = 0, j = siblings.length; i < j; i++) {
		const sibling = siblings[i];
		if (sibling.checked !== true || sibling.indeterminate) {
			all = false;
		}
		if (sibling.checked !== false || sibling.indeterminate) {
			none = false;
		}
	}

	if (all) {
		node.setChecked(true);
	} else if (!all && !none) {
		node.setChecked('half');
	} else if (none) {
		node.setChecked(false);
	}
};

const getPropertyFromData = function(node, prop) {
	const props = node.store.props;
	const data = node.data || {};
	const config = props[prop];

	if (typeof config === 'function') {
		return config(data, node);
	} else if (typeof config === 'string') {
		return data[config];
	} else if (typeof config === 'undefined') {
		return '';
	}
};

let nodeIdSeed = 0;

export default class Node {
	constructor(options) {
		this.id = nodeIdSeed++;
		this.text = null;
		this.checked = false;
		this.indeterminate = false;
		this.data = null;
		this.expanded = false;
		this.parent = null;
		this.visible = true;

		for (let name in options) {
			if (options.hasOwnProperty(name)) {
				this[name] = options[name];
			}
		}

		// internal
		this.level = 0;
		this.loaded = false;
		this.childNodes = [];
		this.loading = false;

		if (this.parent) {
			this.level = this.parent.level + 1;
		}

		const store = this.store;
		if (!store) {
			throw new Error('[Node]store is required!');
		}
		store.registerNode(this);

		const props = store.props;
		if (props && typeof props.isLeaf !== 'undefined') {
			const isLeaf = getPropertyFromData(this, 'isLeaf');
			if (typeof isLeaf === 'boolean') {
				this.isLeafByUser = isLeaf;
			}
		}

		if (store.lazy !== true && this.data) {
			this.setData(this.data);

			if (store.defaultExpandAll) {
				this.expanded = true;
			}
		} else if (this.level > 0 && store.lazy && store.defaultExpandAll) {
			this.expand();
		}

		if (!this.data) return;
		const defaultExpandedKeys = store.defaultExpandedKeys;
		const key = store.key;
		if (key && defaultExpandedKeys && defaultExpandedKeys.indexOf(this.key) !== -1) {
			this.expand(null, store.autoExpandParent);
		}

		if (key && store.currentNodeKey && this.key === store.currentNodeKey) {
			store.currentNode = this;
		}

		if (store.lazy) {
			store._initDefaultCheckedNode(this);
		}

		this.updateLeafState();
	}

	setData(data) {
		if (!Array.isArray(data)) {
			markNodeData(this, data);
		}

		this.data = data;
		this.childNodes = [];

		let children;
		if (this.level === 0 && this.data instanceof Array) {
			children = this.data;
		} else {
			children = getPropertyFromData(this, 'children') || [];
		}

		for (let i = 0, j = children.length; i < j; i++) {
			this.insertChild({ data: children[i] });
		}
	}

	get label() {
		return getPropertyFromData(this, 'label');
	}

	get icon() {
		return getPropertyFromData(this, 'icon');
	}

	get key() {
		const nodeKey = this.store.key;
		if (this.data) return this.data[nodeKey];
		return null;
	}

	insertChild(child, index) {
		if (!child) throw new Error('insertChild error: child is required.');

		if (!(child instanceof Node)) {
			objectAssign(child, {
				parent: this,
				store: this.store
			});
			child = new Node(child);
		}

		child.level = this.level + 1;

		if (typeof index === 'undefined' || index < 0) {
			this.childNodes.push(child);
		} else {
			this.childNodes.splice(index, 0, child);
		}

		this.updateLeafState();
	}

	insertBefore(child, ref) {
		let index;
		if (ref) {
			index = this.childNodes.indexOf(ref);
		}
		this.insertChild(child, index);
	}

	insertAfter(child, ref) {
		let index;
		if (ref) {
			index = this.childNodes.indexOf(ref);
			if (index !== -1) index += 1;
		}
		this.insertChild(child, index);
	}

	removeChild(child) {
		const index = this.childNodes.indexOf(child);

		if (index > -1) {
			this.store && this.store.deregisterNode(child);
			child.parent = null;
			this.childNodes.splice(index, 1);
		}

		this.updateLeafState();
	}

	removeChildByData(data) {
		let targetNode = null;
		this.childNodes.forEach(node => {
			if (node.data === data) {
				targetNode = node;
			}
		});

		if (targetNode) {
			this.removeChild(targetNode);
		}
	}

	expand(callback, expandParent) {
		const done = () => {
			if (expandParent) {
				let parent = this.parent;
				if(parent){
					while (parent.level > 0) {
						parent.expanded = true;
						parent = parent.parent;
					}
				}
			}
			this.expanded = true;
			if (callback) callback();
		};

		if (this.shouldLoadData()) {
			this.loadData((data) => {
				if (data instanceof Array) {
					done();
				}
			});
		} else {
			done();
		}
	}

	doCreateChildren(array, defaultProps = {}) {
		array.forEach((item) => {
			this.insertChild(objectAssign({ data: item }, defaultProps));
		});
	}

	collapse() {
		this.expanded = false;
	}

	shouldLoadData() {
		return this.store.lazy === true && this.store.load && !this.loaded;
	}

	updateLeafState() {
		if (this.store.lazy === true && this.loaded !== true && typeof this.isLeafByUser !== 'undefined') {
			this.isLeaf = this.isLeafByUser;
			return;
		}
		const childNodes = this.childNodes;
		if (!this.store.lazy || this.store.lazy === true && this.loaded === true) {
			this.isLeaf = !childNodes || childNodes.length === 0;
			return;
		}
		this.isLeaf = false;
	}

	setChecked(value, deep) {
		this.indeterminate = value === 'half';
		this.checked = value === true;

		const handleDescendants = () => {
			if (deep) {
				const childNodes = this.childNodes;
				for (let i = 0, j = childNodes.length; i < j; i++) {
					const child = childNodes[i];
					child.setChecked(value !== false, deep);
				}
			}
		};

		if (!this.store.checkStrictly && this.shouldLoadData()) {
			// Only work on lazy load data.
			this.loadData(() => {
				handleDescendants();
			}, {
				checked: value !== false
			});
		} else {
			handleDescendants();
		}

		const parent = this.parent;
		if (!parent || parent.level === 0) return;

		if (!this.store.checkStrictly) {
			reInitChecked(parent);
		}
	}

	getChildren() { // this is data
		const data = this.data;
		if (!data) return null;

		const props = this.store.props;
		let children = 'children';
		if (props) {
			children = props.children || 'children';
		}

		if (data[children] === undefined) {
			data[children] = null;
		}

		return data[children];
	}

	updateChildren() {
		const newData = this.getChildren() || [];
		const oldData = this.childNodes.map((node) => node.data);

		const newDataMap = {};
		const newNodes = [];

		newData.forEach((item, index) => {
			if (item[NODE_KEY]) {
				newDataMap[item[NODE_KEY]] = { index, data: item };
			} else {
				newNodes.push({ index, data: item });
			}
		});

		oldData.forEach((item) => {
			if (!newDataMap[item[NODE_KEY]]) this.removeChildByData(item);
		});

		newNodes.forEach(({ index, data }) => {
			this.insertChild({ data }, index);
		});

		this.updateLeafState();
	}

	loadData(callback, defaultProps = {}) {
		if (this.store.lazy === true && this.store.load && !this.loaded && !this.loading) {
			this.loading = true;

			const resolve = (children) => {
				this.loaded = true;
				this.loading = false;
				this.childNodes = [];

				this.doCreateChildren(children, defaultProps);

				this.updateLeafState();
				if (callback) {
					callback.call(this, children);
				}
			};

			this.store.load(this, resolve);
		} else {
			if (callback) {
				callback.call(this);
			}
		}
	}
}
